HT4100 4.1, 4.5, 4.9 Discussion, did they get better? in Cadillac Engine Technical Discussion; I think I remember reading that the 4.1 improved in it's last years, would appreciate any info on this, was ...
Automobile(s): 1992 eldorado. 2007 dodge magnum hemi r/t
roberts creek b.c. canada
did they get better?
I think I remember reading that the 4.1 improved in it's last years, would appreciate any info on this, was there some engineering improvements
in it's latter years, theres an 85 cdv. for sale in my area for a good price,
is it worth the risk?.
Yes, the intake leaks were inherent to the design and couldn't be "patched". With an aluminum intake mated to iron heads, the different thermal properties of each part raised the likelihood of gasket failure.
On the same note, the later Chevy engines in pickups and vans had an aluminum manifold on iron heads with the same problem. I've replace a bunch of gaskets in those too.
When I was thinking about replacing my 4.1 with a rebuilt engine, the engine rebuilder told me I should get the manifold milled off a bit to insure that it wasn't warped.
I haven't had that problem with my 4.1.
He also told me that for another 300 bucks they could make it a 4.5, and it would work OK in my car.
I've only had one failure on my '90 4.5, it leaked vacuum around one intake port.
I replaced the intake gaskets on my '95 4.9 70k miles ago when I first got it only because I replaced all the top end gaskets to give myself a "Fresh" start. Never failed since. The originals looked ok at the time, not sure if they would have failed by now or not.
Dad's '89 4.5 has 190,000 and still has all original gaskets with no leaks. Seems hit or miss with these.